Effect of the Oxidation of Oils on the Deterioration of Foods

Part I. Oxidation of oils in the model food

Abstract

It is well known that oxidative deterioration of the lipids in the foods is the cause of the development of off flavors during storage. In the present investigation, the models were used by replacing the food with a support of Celite as a structural component. Beef tallow and saury oil as animal fats, safflower oil, rape oil, soybean oil and cotton-seed oil as plant oils, and stearic acid, oleic acid, linoleic acid and linolenic acid as fatty acids were added into the Celite (model food) respectively. Those were stored under different temperatures (30°, 0° and -20°C) for 12 weeks. The course of the oxidation of oil was observed by determining the TBA value and peroxide value.
Subsequently, it was found that the oxidation of saury oil was significantly higher than other oils and that especially in high temperature like 30°C, the oxidation was higher than in lower temperature. Unsaturated fatty acids were unstable even in the low temperature as -20°C. Furthermore, fatty acids of higher degree of unsaturation were oxidized to a great extent.